Telomestatin impairs glioma stem cell survival and growth through the disruption of telomeric G-quadruplex and inhibition of the proto-oncogene, c-Myb.
Telomestatin impairs glioma stem cell survival and growth through the disruption of telomeric G-quadruplex and inhibition of the proto-oncogene, c-Myb.
复制标题
DOI：
10.1158/1078-0432.ccr-11-1795
复制
发表时间：
2012-03-01
期刊：
影响因子：
--
通讯作者：
Nakano I
中科院分区：
文献类型：
--
作者：
Miyazaki T;Pan Y;Joshi K;Purohit D;Hu B;Demir H;Mazumder S;Okabe S;Yamori T;Viapiano M;Shin-ya K;Seimiya H;Nakano I
胶质瘤干细胞（GSC）是多形性胶质母细胞瘤（GBM）的重要治疗靶点。使用患者来源的GSC、非干肿瘤细胞（非GSC）和正常胎儿神经前体在体外和体内评价了G-四链体配体端粒抑素的作用。采用免疫荧光原位杂交（iFISH）和基因芯片技术检测端粒酶抑制素的分子靶点。然后通过体外和体内功能测定以及对90个临床样本的免疫组织化学对数据进行验证。在体内外实验中，端粒酶抑制素通过诱导细胞凋亡而损害GSC干细胞状态的维持。GSC的迁移潜力也受到端粒抑制素治疗的损害。相比之下，正常神经前体细胞和非GSC对端粒抑制素具有相对抗性。GSC衍生的小鼠颅内肿瘤的治疗在体内减小了肿瘤大小，而在正常脑中没有明显的细胞死亡。iFISH显示GSC中的端粒和非端粒DNA均受到端粒抑制素的损伤，但在非GSC中没有。cDNA微阵列鉴定了原癌基因c-Myb作为GSC中端粒酶抑制素的新分子靶点，并且在端粒酶抑制素治疗的荷瘤小鼠脑中的药效学分析显示c-Myb在体内肿瘤中减少。c-Myb的敲除在体外和体内均表型化了经端粒酶抑制素处理的GSC，并且通过过表达恢复c-Myb部分挽救了表型。最后，与正常组织相比，GBM手术标本中c-Myb表达显著升高。这些数据表明，端粒抑制素通过端粒破坏和c-Myb抑制有效地根除GSC，这项研究提出了一种新的GBM的GSC导向治疗策略。
Glioma stem cells (GSC) are a critical therapeutic target of glioblastoma multiforme (GBM). The effects of a G-quadruplex ligand, telomestatin, were evaluated using patient-derived GSCs, non-stem tumor cells (non-GSC), and normal fetal neural precursors in vitro and in vivo. The molecular targets of telomestatin were determined by immunofluorescence in situ hybridization (iFISH) and cDNA microarray. The data were then validated by in vitro and in vivo functional assays, as well as by immunohistochemistry against 90 clinical samples. Telomestatin impaired the maintenance of GSC stem cell state by inducing apoptosis in vitro and in vivo. The migration potential of GSCs was also impaired by telomestatin treatment. In contrast, both normal neural precursors and non-GSCs were relatively resistant to telomestatin. Treatment of GSC-derived mouse intracranial tumors reduced tumor sizes in vivo without a noticeable cell death in normal brains. iFISH revealed both telomeric and non-telomeric DNA damage by telomestatin in GSCs but not in non-GSCs. cDNA microarray identified a proto-oncogene, c-Myb, as a novel molecular target of telomestatin in GSCs, and pharmacodynamic analysis in telomestatin-treated tumor-bearing mouse brains showed a reduction of c-Myb in tumors in vivo. Knockdown of c-Myb phenocopied telomestatin-treated GSCs both in vitro and in vivo, and restoring c-Myb by overexpression partially rescued the phenotype. Finally, c-Myb expression was markedly elevated in surgical specimens of GBMs compared with normal tissues. These data indicate that telomestatin potently eradicates GSCs through telomere disruption and c-Myb inhibition, and this study suggests a novel GSC-directed therapeutic strategy for GBMs.